The U.S. Pat No. 4,745,468 describes a system which allows an evaluation of the answers given by listeners or viewers to questions asked during a radio or television program. The station which broadcasts the program simultaneously transmits, on another radio broadcast channel, an instructions signal containing data representing the question which must be answered, the time lapse provided for formulating an answer and the content and form of the correct answer. The data is loaded remotely in consoles which are provided to the individuals desiring to participate in the broadcast program. For this purpose the consoles comprise a specific means of receiving the instructions signal.
Each console comprises means of timing which compel the participant to formulate an answer within the provided period, this answer being entered into the console by means of a keyboard. In the console, processing means compare the participant's answer with the correct remotely loaded answer, compute the result, winnings or score obtained by the participant and cumulate it with the previously accumulated score.
The cumulated score can then transferred, possibly in encoded form, onto a recording medium for magnetic readout (card with magnetic track) or optical readout (printed or punched sheet). This recording medium thus allows the user of the console to prove participation in the broadcast program and, in association with a server, to validate the obtained result. In exchange, the participant will possibly be able to be awarded a prize in the form of money, an award, a reduction on goods or services, etc. . .
However, this system, as described in the U.S. Pat. No. 4,745,648, has a serious omission in that it does not prevent an individual from recording the broadcast program and the abovementioned instruction signal on a video tape recorder and/or an audio tape recorder, from learning the correct answers to the questions asked, from participating in the program at a later time by means of the recording made, and from then validating the score fraudulently obtained.
The U.S. Pat. No. 4,592,546 describes a similar system allowing viewers to make a bet on the result of an event, such as a football match, before its broadcast by a television station.
In order to bet, the viewers have a console provided with a receiver allowing it to receive radioelectric signals transmitted by a central station. The console is fitted with a real time clock synchronized with an absolute time scale in to order to determine, in the console, the precise time at which the viewer makes a bet. The deadline for betting (kickoff time for a football match for example) is transmitted from the central station to the consoles by radioelectric means and the console only takes account of the bet made by the viewer if this bet is made before the deadline.
For purposes of verification, the console is also provided with 10 counters which are triggered at random times by signals transmitted from the central station. When a player wishes to validate the winnings, the player puts the console into communication with the central station by means of a telephone line and the result is only validated if the state of the counters in the console is at that instant identical with that of similar counters in the central station, whose counting is started at the moment of transmission of the abovementioned signals.
According to this U.S. Pat. No. 4,592,546, the taking into account of the bet fundamentally depends upon the allocation to the latter of a very accurate absolute time by the clock fitted to the console. This clock must therefore be of very high precision (quartz of the type used in clocks for example) as the total drift of this clock over the entire lifetime of the console must not exceed a very low maximum value. The clocks are relatively expensive. The use of clocks with lower performance, and therefore less expensive, combined with a special procedure for adjusting the time of the clock by an authorized organization could be envisaged, but such a system would be a source of difficulties (risks of fraud, dispute, etc. . . ).
Furthermore, the verification procedure aims at avoiding the fraud which would consist in preventing the reception by a console of the real deadline and in allowing a deferred bet by means of a falsification of this deadline. The verification procedure is not truly satisfactory as it is also based on the transmission to the consoles, during the running of the program, of external signals: such a transmission always risks technical difficulties and disputes in the case of defective operation.